This Mentored Research Scientist Award (K01) will enable the candidate to become an independent scientist focusing on maturational changes in bioregulatory sleep-wake processes and their relationship to the development of emotion regulation in early childhood (2-5 years). Career goals are to understand the role of sleep in emotion regulation and to apply basic bioregulatory processes research toward the development of interventions for the prevention of early sleep and emotional problems. Short-term research goals are to examine age-related differences in homeostatic and circadian processes and the effects of sleep (nap) restriction on emotion regulation in young children. The proposed 16-day cross-sectional home-based study with 2- and 5-year-olds (N=36) assesses (a) age-related differences in the accumulation of homeostatic sleep pressure (relationship between extended wakefulness and EEC slow-wave activity in naps taken after 4, 7, 10, 13, and 17 hours on five separate days), circadian phase (salivary melatonin onset), and phase angle (interval between circadian phase and wake time), and (b) the effects of nap restriction on emotion regulation (physiological and behavioral measures). The candidate will complete rigorous training with Mary Carskadon, Ph.D., an expert in sleep-wake regulation in young humans, and co-mentors with expertise in spectral analysis/mathematical modeling (Peter Achermann, Ph.D.) and emotion regulation (Ronald Seifer, Ph.D). Training goals are to develop a broader understanding of bioregulatory and developmental domains underlying sleep, circadian rhythms, and emotion; gain expertise in sleep-wake scoring, EEG spectral analysis, arid analysis of circadian rhythms data; acquire training in administering, coding, and analyzing data from emotion regulation measures; and increase understanding of longitudinal data analytic techniques. With this training, the candidate will be prepared for future longitudinal work on maturation changes in bioregulatory sleep-wake process in association with the development of emotion regulation.